TWI535535B - Abrasive article for lower speed grinding operations - Google Patents

Description

Abrasives for low speed grinding operations

The present application claims priority to and the benefit of U.S. Provisional Patent Application No. 61/668,860, filed on Jul. 6, 2012, and U.S. Provisional Patent Application No. 61/677,655, filed on Jul. 31, 2012. The references are hereby incorporated by reference in their entirety.

The following is directed to abrasive articles, and in particular to bonded abrasive articles suitable for use in low speed grinding operations.

Abrasive tools are generally formed to have abrasive particles contained within a binder material for material removal applications. Superabrasive particles (eg, diamond or cubic boron nitride (CBN)) or seeded (or even unseeded) sintered sol-gel alumina abrasive particles can be used in such abrasive tools (also known as It is a microcrystalline alpha-alumina (MCA) abrasive particle). The binder material may be an organic material such as a resin; or an inorganic material such as a glass or vitrified material. In particular, bonded abrasive tools that use vitrified binder materials and contain MCA grains or superabrasive particles are commercially useful for milling.

Certain bonded abrasive tools, particularly those utilizing vitrified binder materials, require a high temperature forming process (often approximately 1100 ° C or greater) which can adversely affect abrasive particles having MCA. In fact, it has been recognized that at such elevated temperatures necessary to form an abrasive tool, the binder material can react with the abrasive particles (particularly MCA grains) and impair the integrity of the abrasive, thereby Reduce grain sharpness and performance characteristics. As a result, the industry has turned to reducing the formation temperature necessary to form the binder material in order to inhibit high temperature degradation of the abrasive particles during the forming process. The industry continues to demand improved performance of such bonded abrasive articles.

The following are directed to bonded abrasive articles that may be suitable for use in grinding and shaping a workpiece. Notably, the bonded abrasive article of the embodiments herein can incorporate abrasive particles within the glassy binder material. Suitable applications for bonded abrasive articles for use in embodiments herein include grinding operations including, for example, centerless grinding, external grinding, crankshaft grinding, various surface grinding operations, bearing and gear grinding operations, Slow feed grinding and various tool room applications.

According to one embodiment, a method of forming a bonded abrasive article of an embodiment can be initiated by forming a suitable mixture of compound and component to form a binder material. The binder may be formed of a compound of an inorganic material such as an oxide compound. For example, a suitable oxide material can include yttrium oxide (SiO ₂ ). According to an embodiment, the bond material may be formed from no more than about 55 wt% yttrium oxide for the total weight of the bond material. In other embodiments, the amount of cerium oxide can be less, such as no greater than about 54 wt%, no greater than about 53 wt%, no greater than about 52 wt%, or even no greater than about 51 wt%. However, in certain embodiments, the bond material can be at least about 45 wt%, such as at least about 46 wt%, approximately at least about 47 wt%, at least, for the total weight of the bond material. About 48 wt%, or even at least about 49 wt% of cerium oxide is formed. It will be appreciated that the amount of cerium oxide can range between any of the minimum and maximum percentages noted above.

The binder material may also incorporate a certain amount of alumina (Al ₂ O ₃ ). For example, the bond material can comprise at least about 12 wt% alumina for the total weight of the bond material. In other embodiments, the amount of alumina can be at least about 14 wt%, at least about 15 wt%, or even at least about 16 wt%. In some examples, the binder material may comprise alumina in an amount of no greater than about 23 wt%, no greater than about 21 wt%, no greater than about 20 wt%, for the total weight of the binder, Not more than about 19 wt%, or even no more than about 18 wt%. It will be appreciated that the amount of alumina can range between any of the minimum and maximum percentages noted above.

In some examples, the binder material can be formed from a specific ratio between the amount of cerium oxide measured in weight percent and the amount of alumina measured in weight percent. For example, the ratio of bismuth to aluminum can be described by dividing the weight percent of cerium oxide in the binder material by the weight percent of alumina. According to an embodiment, the ratio of cerium oxide to aluminum oxide may be no greater than about 3.2. In other examples, the ratio of cerium oxide to alumina in the binder material can be no greater than about 3.1, no greater than about 3.0, or even no greater than about 2.9. However, in some examples, the binder material can be formed such that the ratio of the weight percent of cerium oxide to the weight percent of alumina is at least about 2.2, such as at least about 2.3, such as at least about 2.4, at least about 2.5. At least about 2.6, or even at least about 2.7. It will be appreciated that the total amount of alumina and cerium oxide can be in the range between any of the minimum and maximum values noted above.

According to an embodiment, the binder material may be formed from a certain amount of boron oxide (B ₂ O ₃ ). For example, the bond material can be combined with no more than about 20 wt% boron oxide for the total weight of the bond material. In other examples, the amount of boron oxide can be less, such as no greater than about 19 wt%, no greater than about 18 wt%, no greater than about 17 wt%, or even no greater than about 16 wt%. However, the binder material may be at least about 11 wt%, such as at least about 12 wt%, at least about 13 wt%, or even at least about 14 wt% boron oxide, based on the total weight of the binder material. form. It will be appreciated that the amount of boron oxide can range between any of the minimum and maximum percentages noted above.

According to an embodiment, the binder material may be formed such that the total weight (ie, the sum) of the weight percent of boron oxide and the weight percent of cerium oxide in the binder material may be the total weight of the binder material. In terms of no more than about 70 wt%. In other examples, the total content of cerium oxide and boron oxide can be no greater than about 69 wt%, such as no greater than about 68 wt%, no greater than about 67 wt%, or even no greater than about 66 wt%. According to a specific embodiment, the total weight percent content of cerium oxide and boron oxide may be at least about 55 wt%, such as at least about 58 wt%, at least about 60 wt%, at least for the total weight of the binder material. About 62 wt%, at least about 63 wt%, at least about 64 wt%, or even at least about 65 wt%. It will be understood that the cerium oxide and the binder material The total weight percent of boron oxide can range between any of the minimum and maximum percentages noted above.

Further, in a specific example, the amount of cerium oxide in the binder material may be greater than the amount of boron oxide as measured by weight percent. Notably, the amount of cerium oxide can be at least about 1.5 times greater, at least about 1.7 times greater, at least about 1.8 times greater, at least about 1.9 times greater, at least about 2.0 times greater, or even at least about 2.5 greater than the amount of boron oxide. Times. However, in one embodiment, the binder material may comprise cerium oxide in an amount of no greater than about 5 times, such as no more than about 4 times greater, no greater than about 3.8 times greater, or even less About 3.5 times. It will be appreciated that the difference in the amount of cerium oxide compared to the amount of boron oxide can be in the range between any of the minimum and maximum values noted above.

According to an embodiment, the binder material may be formed of at least one alkali metal oxy compound (R ₂ O), wherein R represents a metal selected from the group IA elements of the periodic table. For example, the binder material may be formed of an alkali metal oxy-compound (R ₂ O) from the group of compounds including lithium oxide (Li ₂ O), sodium oxide (Na ₂ O), and potassium oxide (K). ₂ O), and cerium oxide (Cs ₂ O), and combinations thereof.

According to an embodiment, the bond material may be formed from an alkali metal oxygen compound having a total content of no greater than about 20 wt% based on the total weight of the bond material. For other bonded abrasive articles according to embodiments herein, the total alkali metal oxygenate content can be no greater than about 19 wt%, no greater than about 18 wt%, no greater than about 17 wt%, no greater than about 16 wt% , or even no more than about 15 wt%. However, in one embodiment, the total alkali metal oxygenate content of the binder material can be at least about 10 wt%, such as at least about 12 Wt%, at least about 13 wt%, or even at least about 14 wt%. It will be appreciated that the binder material comprises a total alkali metal oxygenate content which may range between any of the minimum and maximum percentages noted above.

According to a specific embodiment, the binder material can be formed from no more than about 3 individual alkali metal oxy-compounds (R ₂ O) as indicated above. In fact, certain binder materials may incorporate no more than about 2 alkali metal oxygen compounds in the binder material.

Further, the binder material may be formed such that the individual content of any of the alkali metal oxygen compounds in the binder material is not more than half of the total content of the alkali metal oxygen compound (in weight percent). Further, according to a specific embodiment, the amount of sodium oxide may be greater than the content (weight percent) of lithium oxide or potassium oxide. In a more specific example, the total content of sodium oxide as measured by weight percent may be greater than the sum of the levels of lithium oxide and potassium oxide as measured by weight percent. Further, in an embodiment, the amount of lithium oxide may be greater than the content of potassium oxide.

According to an embodiment, the total amount of alkali metal oxy-compound forming the binder material measured by weight percent may be less than the amount of boron oxide (measured by weight percent) in the binder material. In fact, in certain instances, the total weight percent of alkali metal oxygen compound in the binder material may range from about 0.9 to 1.5, such as between about 0.9 and 1.3, as compared to the total weight percent of boron oxide. Within the range, or even between about 0.9 and about 1.1.

The binder material may be formed from an amount of an alkaline earth metal compound (RO), wherein R represents an element from Group IIA of the Periodic Table of the Elements. For example, the binder material may be combined with an alkaline earth metal oxygen compound such as calcium oxide (CaO), magnesium oxide (MgO), barium oxide (BaO), or even barium oxide (SrO). According to an embodiment, the bond material may comprise no more than about 3.0 wt% alkaline earth metal oxygen compound for the total weight of the bond material. In still other examples, the binder material may comprise less alkaline earth metal oxygen compounds, such as approximately no greater than about 2.8 wt%, no greater than about 2.2 wt%, no greater than about 2.0 wt%, or no greater than about 1.8 wt%. However, according to an embodiment, the binder material may comprise one or more alkaline earth metal oxygen compounds in an amount of at least about 0.5 wt%, such as at least about 0.8 wt%, of at least about 0.8 wt%, based on the total weight of the binder material. About 1.0 wt%, or even at least about 1.4 wt%. It will be appreciated that the amount of alkaline earth metal oxygen compound within the binder material can range between any of the minimum and maximum percentages noted above.

According to an embodiment, the bond material may be formed from no more than about 3 different alkaline earth metal oxygen compounds. In fact, the binder material may comprise no more than two different alkaline earth metal oxygen compounds. In a specific example, the binder material may be composed of two alkaline earth metal oxide compounds composed of calcium oxide and magnesium oxide.

In one embodiment, the binder material may comprise calcium oxide in an amount greater than the amount of magnesium oxide. Additionally, the amount of calcium oxide in the binder material can be greater than the amount of any other alkaline earth metal oxygen compound in the binder material memory.

The binder material may be formed from a combination of an alkali metal oxy compound and an alkaline earth metal oxy compound such that the total content is no greater than about 20 wt% for the total weight of the binder material. In other embodiments, The total content of alkali metal oxy compounds and alkaline earth metal oxy compounds in the binder material may be no greater than about 19 wt%, such as no greater than about 18 wt%, or even no greater than about 17 wt%. However, in certain embodiments, the total content of alkali metal oxygen and alkaline earth metal compounds in the binder material memory may be at least about 12 wt%, such as at least about 13 wt%, such as at least about 14 wt. %, at least about 15 wt%, or even at least about 16 wt%. It will be appreciated that the binder material may have a total content of alkali metal oxy-compounds and alkaline earth metal oxy-compounds in the range between any of the minimum and maximum percentages noted above.

According to an embodiment, the binder material may be formed such that the content of the alkali metal oxygen compound in the binder material memory is greater than the total content of the alkaline earth metal oxygen compound. In a specific embodiment, the binder material may be formed such that the ratio of the total alkali metal oxygen compound content (by weight percent) to the total weight percent of the alkaline earth metal oxygen compound (R ₂ O:RO) is A range between about 5:1 and about 15:1. In other embodiments, the ratio of the total weight percent of the alkali metal oxygen compound to the total weight percent of the alkaline earth metal oxygen compound in the binder material memory may be between about 6:1 and about 14:1. Within the range, such as between about 7:1 and about 12:1, or even between about 8:1 and about 10:1.

According to an embodiment, the bond material may be formed from no more than about 3 wt% phosphorus pentoxide for the total weight of the bond material. In certain other examples, the bond material can comprise no greater than about 2.5 wt%, such as no greater than about 2.0 wt%, no greater than about 1.5 wt%, no greater than the total weight of the bond material. Pentoxide of about 1.0 wt%, no more than about 0.8 wt%, no more than about 0.5 wt%, or even no more than about 0.2 wt% Diphosphorus. In fact, in some instances, the binder material may be substantially free of phosphorus pentoxide. Suitable levels of phosphorus pentoxide can promote certain of the characteristics and abrasive performance characteristics described herein.

According to an embodiment, the binder material may be formed from no more than one composition comprising no more than about 1 wt% of certain oxygen compounds including, for example, MnO ₂ , ZrSiO ₂ , CoAl ₂ O ₄ , and an oxygen compound of MgO. In fact, in a specific embodiment, the binder material may be substantially free of oxygen compounds identified above.

In addition to the binder material disposed within the mixture, the method of forming the bonded abrasive article can further include incorporating a certain type of abrasive particles. According to an embodiment, the abrasive particles may comprise microcrystalline alumina (MCA). In fact, in some instances, the abrasive particles may consist essentially of microcrystalline alumina.

The abrasive particles can have an average particle size of no greater than about 1050 microns. In other embodiments, the average particle size of the abrasive particles can be smaller, such as approximately no greater than 800 microns, no greater than about 600 microns, no greater than about 400 microns, no greater than about 250 microns, no greater than about 225. Micron, no greater than about 200 microns, no greater than about 175 microns, no greater than about 150 microns, or even no greater than about 100 microns. However, the abrasive particles may have an average particle size of at least about 1 micron, such as at least about 5 microns, at least about 10 microns, at least about 20 microns, at least about 30 microns, or even at least about 50 microns, at least about 60 microns, At least about 70 microns, or even at least about 80 microns. It will be appreciated that the average particle size of the abrasive particles can range between any of the minimum and maximum values noted above.

Further referring to abrasive particles utilizing microcrystalline alumina, it will be appreciated that the microcrystalline alumina can be composed of grains having an average grain size set to a submicron size. In fact, the average grain size of the microcrystalline alumina can be no greater than about 1 micron, such as no greater than about 0.5 microns, no greater than about 0.2 microns, no greater than about 0.1 microns, no greater than about 0.08 microns, no greater than about 0.05 microns. Or, even up to about 0.02 microns.

Additionally, the formation of a mixture comprising abrasive particles and a binder material may further comprise the addition of other components, such as fillers, pore formers, and materials suitable for forming the final shaped bonded abrasive article. Some suitable examples of pore-forming materials may include, but are not limited to, hollow alumina balloons; hollow mullite balls; hollow spheres, including hollow glass spheres, hollow ceramic spheres, or hollow polymer spheres. Polymer or plastic material; organic compound; fibrous material, including strands and/or fibers of glass, ceramic, or polymer. Other suitable pore forming materials may include naphthalene, PDB, shells, wood, and the like. In still another embodiment, the filler may include one or more inorganic materials (including, for example, oxides), and specifically may include a crystalline phase or an amorphous phase of zirconia, ceria, titania, and combinations thereof.

The mixture can be shaped after the mixture is suitably formed. Suitable forming methods can include extrusion operations and/or molding operations, and combinations thereof. For example, in one embodiment, the mixture can be formed by cold pressing the mixture in a mold to form a green body.

After the green body is suitably formed, the green body can be sintered at a specific temperature to promote the formation of an abrasive having a glass phase binder material. Product. Notably, the sintering operation can be carried out at a sintering temperature of less than about 1000 °C. In a specific embodiment, the sintering temperature can be less than about 980 °C, such as less than about 950 °C, and specifically in the range between about 800 °C and 950 °C. It will be appreciated that a particularly low sintering temperature can be utilized for the binder components indicated above such that excessive temperatures are avoided and thus the degradation of the abrasive particles during the forming process is limited.

According to a specific embodiment, the bonded abrasive body comprises a binder material having a glass phase material. In a specific example, the bond material can be a single phase glassy material.

The resulting shaped bonded abrasive body can have a specific amount of binder material, abrasive particles, and porosity. Notably, the body of the bonded abrasive article can have a porosity of at least about 42 vol% for the total volume of the bonded abrasive body. In other embodiments, the amount of porosity can be greater, such as at least about 43 vol%, such as at least about 44 vol%, at least about 45 vol%, at least about the total volume of the bonded abrasive body. 46 vol%, at least about 48 vol%, or even at least about 50 vol%. According to an embodiment, the bonded abrasive body can have no more than about 70 vol%, such as no more than about 65 vol%, no more than about 62 vol%, no more than about 60 vol%, no more than about 56 vol%, no Porosity greater than about 52 vol%, or even no greater than about 50 vol%. The bonded abrasive body can comprise a porosity of from about 46% to about 50% of the total volume of the bonded abrasive body, such as from about 46% to about 48% of the total volume of the bonded abrasive body. . It will be appreciated that the bonded abrasive body can have a porosity in the range between any of the minimum and maximum percentages noted above.

According to an embodiment, the bonded abrasive body can have at least about 35 vol% abrasive particles for the total volume of the bonded abrasive body. In other embodiments, the total content of abrasive particles can be greater, such as at least about 37 vol%, or even at least about 39 vol%. According to a specific embodiment, the bonded abrasive body can be formed such that it has no more than about 50 vol% abrasive particles for the total volume of the bonded abrasive body, such as no more than about 48 vol%, or even Not more than about 46 vol%. It will be appreciated that the amount of abrasive particles in the bonded abrasive body can range between any of the minimum and maximum percentages noted above.

In a specific example, the bonded abrasive body is formed such that it contains a minimum amount (vol%) of binder material as compared to the porosity and the amount of abrasive particles. For example, the bonded abrasive body can have no more than about 15 vol% binder material for the total volume of the bonded abrasive body. In other examples, the bonded abrasive body can be formed such that it comprises no more than about 14 vol%, no more than about 13 vol%, or even no more than about 12 vol% of the total volume of the bonded abrasive body. Binder material. In a specific example, the bonded abrasive body can be formed such that it comprises at least about 7 vol%, such as at least about 8 vol%, and approximately at least about 9 vol%, for the total volume of the bonded abrasive body. , or even at least about 10 vol% of binder material.

1 includes an illustration of a plurality of phases in a particular bonded abrasive article memory in accordance with an embodiment. Figure 1 includes vol% binder, vol% abrasive particles, and vol% porosity. Shaded area 101 represents a conventional bonded abrasive article suitable for use in abrasive applications, while shaded area 103 represents the phase content of the bonded abrasive article in accordance with an embodiment herein.

Notably, the phase content of the conventional bonded abrasive articles (i.e., shaded regions 101) is significantly different than the phase content of the bonded abrasive articles of one embodiment. Notably, conventional bonded abrasive articles typically have a maximum porosity in the range between about 40 vol% and 51 vol%, an abrasive particle content of about 42 vol% to 50 vol%, and about 9 vol. % to 20 vol% binder content. Conventional bonded abrasive articles typically have a maximum porosity content of 50 vol% or less because abrasive applications require that the bonded abrasive body have sufficient strength to cope with excessive forces encountered during the grinding process, and A highly porous bonded abrasive body has previously been unable to withstand the forces.

According to one embodiment, the bonded abrasive article can have a much greater porosity than conventional bonded abrasive articles. For example, a bonded abrasive article of an embodiment can have a porosity content ranging between about 51 vol% and about 58 vol% for the total volume of the bonded abrasive body. Moreover, as shown in Figure 1, the bonded abrasive article of one embodiment can have an abrasive in the range of between about 40 vol% and about 42 vol% for the total volume of the bonded abrasive article. The particulate content, and a particularly low binder content in the range between about 2 vol% and about 9 vol%.

Notably, the bonded abrasive body of the embodiments herein can have particular features that are different from conventional bonded abrasive bodies. In particular, the bonded abrasive articles herein can have a specific content of porosity, abrasive particles, and binder while exhibiting particular mechanical characteristics that make them suitable for particular applications, such as abrasive applications. For example, in one embodiment, the bonded abrasive body can have a specific modulus of rupture (MOR) that can correspond to a particular modulus of elasticity (MOE). For example, for With a MOE of less than about 40 GPa, the bonded abrasive body can have a MOR of at least 45 MPa. In one embodiment, for a 40 GPa MOE, the MOR can be at least about 46 MPa, such as at least about 47 MPa, at least about 48 MPa, at least about 49 MPa, or even at least about 50 MPa. However, for a 40 GPa MOE, the bonded abrasive body can have a MOR of no greater than about 70 MPa, such as no greater than about 65 MPa, or no greater than about 60 MPa. It will be appreciated that the MOR can be within the range between any of the minimum and maximum values given above.

In another embodiment, for certain bonded abrasive bodies having an MOE of 45 GPa, the MOR can be at least about 45 MPa. In fact, for certain bonded abrasive bodies having an MOE of 45 GPa, the MOR can be at least about 46 MPa, such as at least about 47 MPa, at least about 48 MPa, at least about 49 MPa, or even at least about 50 MPa. However, for a MOE of 45 GPa, the MOR may be no greater than about 70 MPa, no greater than about 65 MPa, or no greater than about 60 MPa. It will be appreciated that the MOR can be within the range between any of the minimum and maximum values given above.

In another embodiment, for certain bonded abrasive bodies having an MOE of 45 GPa, the MOR can be at least about 45 MPa. In fact, for certain bonded abrasive bodies having an MOE of 45 GPa, the MOR can be at least about 46 MPa, such as at least about 47 MPa, at least about 48 MPa, at least about 49 MPa, or even at least about 50 MPa. However, for a MOE of 45 GPa, the MOR may be no greater than about 70 MPa, no greater than about 65 MPa, or no greater than about 60 MPa. It will be appreciated that the MOR can be within the range between any of the minimum and maximum values given above.

Standard three can be used for samples of size 4" x 1" x 0.5" A point bend test is used to measure the MOR, where in addition to the sample size, the load is typically applied to a 1" x 0.5" plane according to ASTM D790. The damage load can be recorded and the MOR calculated using standard equations. The MOE can be calculated by measuring the natural frequency of the composite using a GrindoSonic instrument or similar device in accordance with standard procedures in the abrasive wheel industry.

In one embodiment, the bonded abrasive body can have an intensity ratio that is a measure of the MOR divided by the MOE. In a specific example, the strength ratio (MOR/MOE) of a particular bonded abrasive body can be at least about 0.8. In other examples, the intensity ratio can be at least about 0.9, such as at least about 1.0, at least about 1.05, at least about 1.10. However, the intensity ratio can be no greater than about 3.00, such as no greater than about 2.50, no greater than about 2.00, no greater than about 1.70, no greater than about 1.50, no greater than about 1.40, or no greater than about 1.30. It will be appreciated that the strength ratio of the bonded abrasive bodies can range between any of the minimum and maximum values noted above.

According to an embodiment, the bonded abrasive body can be adapted for a particular grinding operation. For example, the bonded abrasive system of the embodiments herein has been found to be suitable for use in a grinding operation. In fact, the bonded abrasive bodies can be utilized without damaging the workpiece and providing suitable or improved abrasive performance.

The abrasive capabilities of the bonded abrasive body referred to herein may involve a variety of grinding operations such as centerless grinding, external grinding, cranking, various surface grinding operations, bearing and gear grinding operations, slow feed grinding, and various tool rooms. Grinding process. Additionally, suitable workpieces for such grinding operations can include inorganic or organic materials. In a specific example, the workpiece can be packaged Includes a metal, metal alloy, plastic, or natural material. In an embodiment, the workpiece may comprise an iron metal, a non-ferrous metal, a metal alloy, a metal superalloy, and combinations thereof. In another embodiment, the workpiece can comprise an organic material comprising, for example, a polymeric material. In still other examples, the workpiece can be a natural material including, for example, wood.

Some versions of the wheel size of the abrasive articles can vary in diameter from greater than about 4.5 inches to about 54 inches. A typical stock removal amount can vary from about 0.0001 inches to about 0.500 inches, depending on the application.

In a specific example, it has been pointed out that the bonded abrasive body is capable of grinding the workpiece at a particularly high removal rate. For example, in one embodiment, the bonded abrasive body may be at least about 0.4 ⁱⁿ³ / min / inch (in ³ / min / in) at ^{(258 mm 3 / min / mm} ) material removal rate grinding operation . In other embodiments, the material removal rate can be at least about 0.45 inches ³ /min / inch (290 mm ³ /min / mm), such as at least about 0.5 inch ³ / minute / inch (322 mm ³ /min / mm) At least about 0.55 inch ³ /min / inch (354 mm ³ /min / mm), or even at least about 0.6 inch ³ /min / inch (387 mm ³ /min / mm). However, for some bonded abrasive body, the material removal rate may not be greater than about 1.5 ⁱⁿ³ / min / inch ^{(967 mm 3 / min / mm} ), such as not greater than about 1.2 ⁱⁿ³ / min / inch (774 mm ³ /min/mm), no more than about 1.0 inch ³ /min / inch (645 mm ³ /min / mm), or even no more than about 0.9 inch ³ /min / inch (580 mm ³ /min / mm). It will be appreciated that the bonded abrasive body of the present application can grind the workpiece at a material removal rate in the range between any of the minimum and maximum values noted above.

During certain grinding operations, it has been pointed out that the bonded abrasive body of the present application can be ground at a specific depth of cut (DOC) or (Zw). For example, the bonded abrasive body can achieve a depth of cut of at least about 0.003 inches (0.0762 mm). In other examples, the bonded abrasive body can achieve at least about 0.004 inches (0.102 mm), such as at least about 0.0045 inches (0.114 mm), at least about 0.005 inches (0.127 mm), or even at least about during a grinding operation. Cutting depth of 0.006 inches (0.152 mm). It will be appreciated that the depth of cut using the abrasive abrasive body herein can be no greater than about 0.01 inches (0.254 mm), or no greater than about 0.009 inches (0.229 mm). It will be appreciated that the depth of cut can be within a range between any of the minimum and maximum values noted above.

In other embodiments, it has been pointed out that the bonded abrasive body can grind the workpiece at a maximum power of no more than about 10 Hp (7.5 kW) while utilizing the grinding parameters indicated above. In other embodiments, the maximum power during the grinding operation can be no greater than about 9 Hp (6.8 kW), such as no greater than about 8 Hp (6.0 kW), or even no greater than about 7.5 Hp (5.6 kW).

According to another embodiment, the bonded abrasive article of the embodiments herein has been shown to have superior corner retention capabilities (especially as compared to conventional bonded abrasive articles) during the grinding operation. In fact, the bonded abrasive body can have a corner retention factor of no greater than about 0.07 inches at a depth of cut (Zw) of at least about 1.8, the depth of cut corresponding to 0.00255 inches. Inch / second, radians. Notably, as used herein, a depth of cut of 1.0 corresponds to 0.00142 inches/second, a degree of curvature, and a depth of cut (Zw) of 1.4 corresponds to 0.00198 inches/second, radian. It will be appreciated that the corner retention factor is a measure of the change in radius in inches after 5 grindings of a 4330 V workpiece (the workpiece is a NiCrMoV tempered high strength steel alloy) at a particular depth of cut. In certain other embodiments, the bonded abrasive article exhibits a corner retention factor of no greater than about 0.06 inches, such as no greater than about 0.05 inches and no greater than about 0.04 inches, for a depth of cut of at least about 1.80.

In one embodiment, the abrasive article can include a bonded abrasive body having abrasive particles contained within a binder material. The bonded abrasive body can include an elastic modulus (MOE) of an abrasive particle-binder material interface of at least about 225 GPa. The bonded abrasive body can be configured to grind a workpiece comprising metal at a speed of less than about 60 m/s.

For example, the MOE of the abrasive particle-binder material interface can be at least about 250 GPaa, such as at least about 275 GPa, or even at least about 300 GPa. Alternatively, the MOE of the abrasive particle-binder material interface may be no greater than about 350 GPa, such as no greater than about 325 GPa, or even no greater than about 320 GPa.

In another embodiment, the abrasive article can include a bonded abrasive body having abrasive particles contained within a binder material. The bonded abrasive body can include a hardness of at least about 13 GPa of abrasive grain-binder material interface. The bonded abrasive body can be configured to grind a workpiece comprising metal at a speed of less than about 60 m/s. In other examples, the hardness of the abrasive particle-binder material interface can be at least about 14 GPa, or even at least about 15 GPa. Alternatively, the hardness of the abrasive particle-binder material interface may be no greater than about 20 GPa, such as no greater than about 18 GPa, or even no greater than about 16 GPa.

In still another example, the bonded abrasive body can include a surface finish of no greater than about 125 Ra.

The bonded abrasive body can be performed at a cross feed rate (Z'w) of at least about 1.0 inches per minute. For example, Z'w can be no greater than about 1.4 inches per minute, such as no greater than about 1.8 inches per minute, no greater than about 2.0 inches per minute, or even 2.2 inches per minute.

In one version, the bonded abrasive body can include a material removal rate of at least about 0.235 inch ³ /minute.

Embodiments of the abrasive article can include a bonded abrasive body having abrasive particles contained within a binder material. The bonded abrasive body can include a grinding coefficient defined as a change in x-axis radius as a function of the transverse feed rate. The coefficient of grinding can be no greater than about 0.040. The bonded abrasive body can be configured to grind a workpiece comprising metal at a speed of less than about 60 m/s. The coefficient of grinding may be a grinding coefficient of no greater than about 0.035, such as no greater than about 0.030, or even no greater than about 0.028.

In a specific embodiment, the bonded abrasive body can include an x-axis corner retention factor of no greater than about 0.080 inches. For example, the x-axis corner retention factor can be no greater than about 0.070 inches, such as no greater than about 0.060 inches, no greater than about 0.050 inches, or even no greater than about 0.042 inches.

The corner retention factor can be expressed as a change in the radius of the wheel. The ratio. For example, for a wheel having a 7 inch diameter (ie, a 3.5 inch radius), the 0.080 inch x-axis corner retention factor represents the following change: 1-(3.5-0.08) / 3.5 = 2.3% variation of the x-axis radius of the wheel . For the x-axis corner retention factor of 0.07, 0.06, 0.05, and 0.042, the x-axis radius variation of the wheel is correspondingly 2%, 1.7%, 1.4%, and 1.2%. Thus, the bonded abrasive body can have a x-axis radius variation of no more than 3%. For example, the bonded abrasive body can have a x-axis radius change of no greater than 2.5%, such as no greater than about 2%, no greater than about 1.7%, no greater than about 1.5%, or even no greater than about 1.3%.

Other embodiments of the bonded abrasive body can include a grinding coefficient defined as a change in the y-axis radius as a function of the transverse feed rate. The coefficient of grinding can be no greater than about 0.018. Other examples of the abrasive coefficient can be a grinding coefficient of no greater than about 0.016, such as no greater than about 0.014, a grinding coefficient of no greater than about 0.012, or even no greater than about 0.010.

In one embodiment, the bonded abrasive body can include a y-axis corner retention factor of no greater than about 0.033 inches, such as no greater than about 0.030 inches, no greater than about 0.025 inches, or even no greater than about 0.024 inches.

This corner retention factor can be expressed as a percentage change in the radius of the wheel. For example, for a wheel having a 7 inch diameter (ie, 3.5 inch radius), the 0.033 inch y-axis corner retention factor represents the following change: 1-(3.5-0.033) / 3.5 = 0.94% variation of the y-axis radius of the wheel. For the y-axis corner retention factor of 0.03, 0.025, and 0.024, the y-axis radius variation of the wheel is correspondingly 0.86%, 0.71%, and 0.69%.

Thus, the bonded abrasive body can have no more than about 1% The y-axis radius changes. For example, the bonded abrasive body can have a change in x-axis radius of no greater than about 0.9%, such as no greater than about 0.8%, or even no greater than about 0.7%.

Other versions of the abrasive article can include requiring at least about 3% less dressing than conventional OD abrasive grinding wheels, such as at least about 4%, at least about 5%, or even at least about 6% less than conventional OD abrasive grinding wheels. Trimmed body.

In another example, the body can require at least about 5% less cycle time than conventional OD abrasive grinding wheels. For example, the body can require at least about 10% less cycle time, such as at least about 15%, or even at least about 18% of the cycle time, compared to conventional OD abrasive grinding wheels.

Embodiments of the abrasive article can have a bonded abrasive body that can be configured to grind a workpiece comprising metal at a speed of less than about 55 m/s. For example, the speed can be less than about 50 m/s, such as less than about 45 m/s, or even less than about 40 m/s. In still other versions, the speed may be at least about 35 m/s, such as at least about 40 m/s, at least about 45 m/s, or even at least about 50 m/s.

The abrasive article can have a body including a wheel having an outer diameter of from about 24 inches to about 30 inches, such as from about 18 inches to about 30 inches, from about 10 inches to about 36 inches, or even about 5 inches. Up to about 54 inches.

Other embodiments of the abrasive article can include a binder material comprising a single phase glassy material. Some versions of the bonded abrasive body can include at least about the total volume of the bonded abrasive body 42 vol% porosity, such as no more than about 70 vol% porosity.

The bonded abrasive body can include at least about 35 vol% abrasive particles of the total volume of the bonded abrasive body. In another example, the bonded abrasive body can comprise no more than about 15 vol% binder material, based on the total volume of the bonded abrasive body.

An example of the binder material may be formed from no more than about 20 wt% boron oxide (B ₂ O ₃ ) for the total weight of the binder material. In another version, the binder material may comprise not greater than about 3.2 of silicon oxide (SiO ₂₎ weight percent alumina (Al ₂ O ₃₎ by weight percent _{(SiO 2: Al 2 O 3} ) ratio. The binder material can be formed from no more than about 3.0 wt% phosphorus pentoxide (P ₂ O ₅ ). Alternatively, the binder material may be substantially free of phosphorus pentoxide (P ₂ O ₅ ).

Other embodiments of the binder material can be formed from an alkaline earth metal oxygen compound (RO). For example, the total amount of alkaline earth metal oxide (RO) present in the binder material may be no greater than about 3.0 wt%. The binder material may be formed from no more than about 3 different alkaline earth metal oxygen compounds (RO) selected from the group consisting of calcium oxide (CaO), magnesium oxide (MgO), oxidation. Barium (BaO), barium oxide (SrO). The binder material may further comprise an alkali metal oxy compound (R ₂ O) selected from the group consisting of lithium oxide (Li ₂ O), sodium oxide (Na ₂ O), Potassium oxide (K ₂ O), and cerium oxide (Cs ₂ O) and combinations thereof. The binder material may be formed from a total amount of no more than about 20% by weight of an alkali metal oxy compound (R ₂ O). Alternatively, the binder material may comprise no more than about 3 alkali metal oxy-compounds (R ₂ O). In another example, the content (wt%) of any alkali metal oxy-compound in the binder material memory may be no more than half of the total content (wt%) of the alkali metal oxide.

In still other embodiments, the adhesive material not greater than about 55 wt% of silicon oxide (SiO ₂₎ is formed. The bond material can be formed from at least about 12 wt% alumina (Al ₂ O ₃ ). The binder material may also be formed of at least one alkali metal oxygen compound (R ₂ O) and at least one alkaline earth metal oxygen compound (RO), wherein the total content of the alkali metal oxygen compound and the alkaline earth metal oxygen compound is not more than about 20 Wt%.

Some examples of binders may be formed from boron oxide (B ₂ O ₃ ) and cerium oxide (SiO ₂ ), wherein the total content of boron oxide and cerium oxide may be no greater than about 70 wt%. The content of cerium oxide (SiO ₂ ) may be greater than the content of boron oxide.

In a particular version, the binder may be formed from a composition comprising no more than about 1 wt% of an oxygen compound selected from the group consisting of MnO ₂ , ZrSiO ₂ , COAl ₂ O ₄ , and MgO. The binder may be formed of a composition substantially free of oxygen compounds selected from the group consisting of MnO ₂ , ZrSiO ₂ , CoAl ₂ O ₄ , and MgO. Additionally, the bonded abrasive body can be sintered at a temperature of no greater than about 1000 °C.

Embodiments of the binder material can include a ratio of weight percent of cerium oxide (SiO ₂ ) to weight percent of alumina (Al ₂ O ₃ ) (SiO ₂ :Al ₂ O ₃ ) of from about 2.4 to about 3.5. The binder material can include a trace amount (<1%) of each of the following: Fe ₂ O ₃ , TiO ₂ and Mg, and combinations thereof. The binder material may comprise silicon oxide is from about 32 to about 52 (SiO ₂₎ weight percent of the weight percent CaO: ratio (SiO ₂ CaO) a. The binder material may also include a ratio of weight percent of cerium oxide (SiO ₂ ) to weight percent of LiO ₂ (SiO ₂ :LiO ₂ ) of from about 9.6 to about 26. In another example, the binder material may comprise silicon oxide of from about 4.8 to about 10.4 (SiO ₂₎ weight percent of the weight percent of Na ₂ O (SiO _2: Na ₂ O) ratio. The binder material may comprise a ratio of weight percent cerium oxide (SiO ₂ ) to weight percent K ₂ O (SiO ₂ : K ₂ O) of from about 9.6 to about 26. The binder material may also include a ratio of weight percent of cerium oxide (SiO ₂ ) to weight percent of B ₂ O ₃ (SiO ₂ :B ₂ O ₃ ) of from about 2.8 to about 5.2.

Embodiments of the binder material can include a ratio of weight percent of alumina (Al ₂ O ₃ ) to weight percent of CaO (Al ₂ O ₃ :CaO) of from about 10 to about 20. The binder material may comprise a ratio of weight percent of alumina (Al ₂ O ₃ ) to weight percent of LiO ₂ (Al ₂ O ₃ :LiO ₂ ) of from about 3 to about 10. The binder material may also include a ratio of weight percent of alumina (Al ₂ O ₃ ) to weight percent of Na ₂ O (Al ₂ O ₃ :Na ₂ O) of from about 1.5 to about 4. An example of the binder material may include a ratio of weight percent of alumina (Al ₂ O ₃ ) to weight percent of K ₂ O (Al ₂ O ₃ : K ₂ O) of from about 3 to about 10. The binder material may also include a ratio of weight percent of alumina (Al ₂ O ₃ ) to weight percent of B ₂ O ₃ (Al ₂ O ₃ : B ₂ O ₃ ) of from about 0.9 to about 2.

In another example, the bond material can include a ratio of CaO weight percent to LiO ₂ weight percent (CaO:LiO ₂ ) of from about 0.2 to about 0.75. The binder material may comprise a ratio of CaO weight percent to Na ₂ O weight percent (CaO: Na ₂ O) of from about 0.1 to about 0.3. The binder material may also include a ratio of CaO weight percent to K ₂ O weight percent (CaO: K ₂ O) of from about 0.2 to about 0.75. Additionally, the bond material can include a ratio of CaO weight percent to B ₂ O ₃ weight percent (CaO: B ₂ O ₃ ) of from about 0.16 to about 0.15.

Other embodiments of the bond material can include a ratio of Li ₂ O weight percent to about Na ₂ O weight percent (Li ₂ O: Na ₂ O) of from about 0.2 to about 1. The binder material may comprise a ratio of Li ₂ O weight percent to K ₂ O weight percent (Li ₂ O: K ₂ O) of from about 0.4 to about 2.5. The bond material may also include a ratio of Li ₂ O weight percent to B ₂ O ₃ weight percent (Li ₂ O: B ₂ O ₃ ) of from about 0.12 to about 0.5.

A specific embodiment of the binder material can include a ratio of weight percent of Na ₂ O to weight percent of K ₂ O (Na ₂ O: K ₂ O) of from about 1 to about 5. The binder material may also include a ratio of weight percent of Na ₂ O to weight percent of B ₂ O ₃ (Na ₂ O:B ₂ O ₃ ) of from about 0.3 to about 1. Further, the binder material may comprise from about 0.12 to about 0.5 percent by weight of K ₂ O ₂ O ₃ weight percent _{B (CaO: B 2 O 3} ) ratio.

Other examples of abrasive articles can include a bonded abrasive body having abrasive particles contained within a binder material comprising no more than about 20 wt% boron oxide (B) ₂ O ₃ ) formed, having a weight percentage of cerium oxide (SiO ₂ ): a ratio by weight of alumina (Al ₂ O ₃ ) of not more than about 3.2 (by weight percent), and having phosphorus pentoxide (P) ₂ O ₅ ) no greater than about 3.0 wt%, wherein the bonded abrasive body has a porosity of at least about 42 vol% of the total volume of the bonded abrasive body. The bonded abrasive body may be capable of grinding a workpiece containing metal at a speed of less than about 60 m/s.

An embodiment of a method of grinding an abrasive article can be To include forming a bonded abrasive body having abrasive particles contained within a binder material such that the bonded abrasive body comprises an elastic modulus (MOE) of an abrasive particle-binder material interface of at least about 225 GPa ). The method can include grinding the workpiece comprising the metal with the bonded abrasive body at a speed of less than about 60 m/s.

Another embodiment of a method of grinding an abrasive article can include forming a bonded abrasive body having abrasive particles contained within a binder material such that the bonded abrasive body comprises an abrasive of at least about 13 GPa The hardness of the interface of the particle-binder material. The method can include grinding the workpiece comprising the metal with the bonded abrasive body at a speed of less than about 60 m/s.

Yet another embodiment of the method of grinding an abrasive article can include forming a bonded abrasive body having abrasive particles contained within a binder material such that the bonded abrasive body includes being defined as The grinding coefficient of the x-axis radius change resulting from the change in the traverse feed rate, and for a cross feed rate (Z'w) of at least about 1.0 inch/minute, the grinding coefficient is no greater than about 0.040. The method can include grinding the workpiece comprising the metal with the bonded abrasive body at a speed of less than about 60 m/s.

A method of grinding an abrasive article can also include forming a bonded abrasive body having abrasive particles contained within a binder material such that the bonded abrasive body includes a definition of the transverse feed rate. The grinding coefficient of the varying y-axis radius is varied, and for a cross feed rate (Z'w) of at least about 1.0 inches per minute, the coefficient of grinding is no greater than about 0.018. The method can include using the bonded at a speed of less than about 60 m/s The abrasive body grinds the workpiece containing the metal.

Still another method of grinding an abrasive article can include forming a bonded abrasive body having abrasive particles contained within a binder material, the binder material being no greater than about 20 wt % of boron oxide (B ₂ O ₃ ) is formed, having a weight percentage of cerium oxide (SiO ₂ ): a ratio by weight of alumina (Al ₂ O ₃ ) of not more than about 3.2 (by weight percent), and having The phosphorus pentoxide (P ₂ O ₅ ) is no greater than about 3.0 wt%, wherein the bonded abrasive body has a porosity of at least about 42 vol% of the total volume of the bonded abrasive body. The method can include grinding the workpiece comprising the metal with the bonded abrasive body at a speed of less than about 60 m/s.

The disclosure will be better understood, and its numerous features and advantages will become apparent to those skilled in the art.

1 includes graphical representations of percent porosity, percent abrasive, and percent binder for a bonded abrasive body of the prior art and a bonded abrasive body in accordance with embodiments herein.

Figure 2 includes a photograph showing the modulus and hardness tests of abrasive particles, binders, and their interfaces.

3 includes an abrasive, binder, and abrasive-binder interface modulus of elasticity (MOE) for two conventional bonded abrasive articles as compared to bonded abrasive articles in accordance with an embodiment herein. Chart.

4 includes abrasives, binders, and mills for two conventional bonded abrasive articles as compared to bonded abrasive articles in accordance with an embodiment herein. A graph of the hardness of the material-binder interface.

Figure 5 includes a schematic diagram showing an abrasive article with loss of shape along both the x-axis and the y-axis.

Figure 6 includes a plot of surface finish Ra and cross feed rate (Z&apos;w) for a conventional bonded abrasive article and a bonded abrasive article in accordance with an embodiment.

Figure 7 includes a plot of material removal and cross feed rate (Z&apos;w) for five times of grinding for a conventional bonded abrasive article and a bonded abrasive article according to one embodiment.

Figure 8 includes plots showing the x-axis radius change and the cross feed rate (Z&apos;w) for the corner retention factor of a conventional bonded abrasive article and a bonded abrasive article in accordance with an embodiment.

Figure 9 includes a plot showing the change in the y-axis radius and the cross feed rate (Z&apos;w) for the corner retention factor of a conventional bonded abrasive article and a bonded abrasive article according to an embodiment.

Figure 10 includes a graph of the number of parts per trim for a conventional bonded abrasive article and a bonded abrasive article in accordance with an embodiment.

Figure 11 includes a graph of cycle times for a conventional bonded abrasive article and a bonded abrasive article in accordance with an embodiment.

The use of the same reference symbols in different drawings indicates the same or the same.

Instance Example 1

The life or performance of the wheel in an OD grinding application may depend on the number of grindings it can sustain, or the number of parts that can be ground before the wheel loses its shape or corner retention capability, which will also affect part quality. The life of the wheel may also be related to the trim frequency required to create a new surface for subsequent grinding operations. The shape retention or corner retention capabilities of the wheel may also be related to the ability of the binder to retain the die and retain its superior quality for efficient grinding operations. In this example, a grinding wheel with 38A fused alumina abrasive particles using different binders was tested. The test device used a MTS nanoindenter XP with a B-type indenter tip. For each sample, an indentation was attempted at 20 locations along a double line (see Figure 2) extending from one abrasive grain, across the grain boundary to the binder zone and then into the next abrasive particle. The spacing between the indentations in a row is 10 microns and the rows themselves are separated by a distance of 10 microns. The indentation continues to a depth of 1 micron.

Figures 3 and 4 depict the comparison of modulus of elasticity (MOE) and hardness for three different binders, respectively. Drawings 1301, 1302, and 1303 represent the MOE of the abrasive, binder, and abrasive-binder interface, respectively, of a sample of the bonded abrasive article formed in accordance with an embodiment herein. This sample has a binder content ranging from about 7 vol% to about 12 vol% of the total volume of the bonded abrasive body. Additionally, the sample has a porosity ranging from about 46 vol% to about 50 vol% of the total volume of the bonded abrasive body.

In FIG. 3, a first conventional sample CS1 produces MOE values of 1305, 1306, and 1307 for its abrasive, binder, and abrasive-binder interfaces, respectively. Sample CS1 as a VS product available from Saint-Gobain (Saint A bonded abrasive article commercially available from Gobain Corporation. The second conventional sample, CS2, is a bonded abrasive article commercially available from Saint-Gobain as a VH product. Sample CS2 produced MOE values of 1310, 1311, and 1312 for its abrasive, binder, and abrasive-binder interfaces, respectively.

As shown in FIG. 3, the interface MOE 1303 of this embodiment significantly outperforms the interfaces MOE 1307 and 1312 of the conventional samples CS1 and CS2, respectively. Such results show that the MOE of the abrasive-binder interface of the bonded abrasive article formed in accordance with embodiments herein is significantly improved over prior art conventionally bonded abrasive articles.

In FIG. 4, plots 1401, 1402, and 1403 represent the hardness of the abrasive, binder, and abrasive-binder interface of the sample of bonded abrasive article formed in accordance with the embodiment of FIG. 3, respectively. The first conventional sample CS1 produces hardness values 1405, 1406, and 1407 for its abrasive, binder, and abrasive-binder interfaces, respectively. Sample CS1 is identical to the sample disclosed above for Figure 3. Similarly, the second conventional sample CS2 produces hardness values 1410, 1411, and 1412 for its abrasive, binder, and abrasive-binder interfaces, respectively. Sample CS2 is identical to the sample disclosed above for Figure 3.

As shown in FIG. 4, the interface hardness 1403 of this embodiment is significantly better than the interface hardnesses 1407 and 1412 of the conventional samples CS1 and CS2, respectively. Such results show that the hardness of the abrasive-binder interface of the bonded abrasive article formed in accordance with embodiments herein is significantly improved over prior art conventionally bonded abrasive articles.

Therefore, the new binder has a higher modulus and hardness. This pair The weaker parts of the grinding wheel (binder and interface) are of particular interest. An improvement in the modulus and hardness of the interface can illustrate the strengthening of the interface and showing that it has better connectivity to the abrasives. These designs help to increase the life of the grinding wheel under aggressive grinding conditions.

Example 2

Samples of four 7-inch wheels were prepared for this corner retention application and testing. These four samples included three different conventional binders and a binder according to an embodiment herein. All four samples include 38A fused aluminaite grains, and each includes from about 7 vol% to about 12 vol% binder content, and from about 46% to about 50%, based on the total volume of the bonded abrasive body. Porosity. These conventional samples used the same VS and VH binders used in Example 1. Table 1 contains more details regarding the test conditions used in Example 2.

The four samples were tested on a Bryant grinder in a corner-retained configuration. The wheel speed is 50.36 m/s. The test material was 3.745 inch OD 4330V steel (R _c = 28-32). The test material speed was 1.15 m/s. The grinding mode was externally inserted using a 0.100 inch grinding width. Each wheel is trimmed by means of a reverse plated diamond roller. The cross feed rate was adjusted to give a target material removal rate (Z'W) of 1.0, 1.4 and 1.8 inches ³ /min / inch. At the target feed rate, five consecutive untrimmed radial grinds were performed for each test wheel. Surface finish and waviness are obtained from the processed material after the last grinding. For the measurement of the corner radius and radial wear, after each grinding, the Formica blank in which the contour of the wheel was recorded was ground using a test wheel. The measured value is obtained from the blank.

Figure 6 includes plots of surface finish Ra and cross feed rate (Z&apos;w) for three conventional bonded abrasive articles 1606, 1601, and 1602 and bonded abrasive article 1605 of the present embodiment. The bonded abrasive body 1605 of the present embodiment includes a surface finish of no more than about 85 Ra at a cross feed rate (Z'w) of 1.4 inches per minute. In contrast, articles 1606, 1601, and 1602 exhibited a surface finish of at least about 125 Ra at a cross feed rate (Z'w) of 1.4 inches per minute.

Figure 7 includes material removal and cross feed rate (Z'w) in 5 grindings for the same three conventional bonded abrasive articles 1700, 1701, and 1702 and bonded abrasive article 1705 of the present embodiment. Drawing. 1705 bonded abrasive body comprises at least about 0.241 inches material removal rate of ³ / min at an infeed rate (Z'w) 1.8 inches / minute. In contrast, conventional articles 1700, 1701, and 1702 exhibited a material removal rate of no greater than about 0.235 inch ³ /minute at a cross feed rate (Z'w) of 1.8 inches per minute.

A schematic diagram of corner wear or radius measurement changes is shown in FIG. Size 1500 represents the original size of a sample along the x-axis (ie, 0.875) The axial width of the inch, and the dimension 1501 represents the post-grinding size of the sample along the x-axis. Similarly, dimension 1502 represents the original dimension of a sample along the y-axis (i.e., 7 inches in diameter), while dimension 1503 represents the post-milled dimension of the sample along the y-axis.

Figure 8 includes x-axis radius variation and cross feed rate (Z' for the same three conventional bonded abrasive articles 1800, 1801, and 1802 and the bonded abrasive article 1805 of the present embodiment showing a corner retention factor. w) drawing. The bonded abrasive body 1805 of the present embodiment includes an x-axis corner retention factor of about 0.042 inches at a cross feed rate (Z&apos;w) of 1.8 inches/minute. In contrast, conventional articles 1800, 1801, and 1802 exhibit an x-axis corner retention factor of at least about 0.080 inches at a cross feed rate (Z&apos;w) of 1.8 inches/minute.

Additionally, the bonded abrasive body 1805 includes a grinding coefficient defined as a change in x-axis radius that occurs as a function of the transverse feed rate. These grinding coefficients are essentially the average slope of the line in Figure 8. For example, for the body 1805, the grinding coefficient has a molecule of 0.042-0.019=0.023. The denominator is 1.80 - 1.00 = 0.80. 0.023 / 0.80 = a grinding coefficient of about 0.029. In contrast, articles 1800, 1801, and 1802 have a grinding coefficient of at least about 0.050.

Similarly, Figure 9 includes y-axis radius variations and cross feed rates for the same three conventional bonded abrasive articles 1900, 1901, and 1902 and bonded abrasive article 1905 of the present embodiment showing a corner retention factor. (Z'w) drawing. The body 1905 exhibited a y-axis corner retention factor of about 0.024 inches at a cross feed rate (Z&apos;w) of 1.8 inches/minute. article 1900, 1901, and 1902 have a y-axis corner retention factor of at least about 0.033 inches at a cross feed rate (Z&apos;w) of 1.8 inches/minute.

The grinding coefficient can also be calculated according to Figure 9. For example, for body 1905, the coefficient of grinding has a molecule of from 0.024 to 0.016 = 0.008. The denominator is 1.80 - 1.00 = 0.80. 0.008 / 0.80 = a grinding coefficient of about 0.01. In contrast, articles 1900, 1901, and 1902 have a grinding coefficient of at least about 0.0188.

Thus, the change in corner radius along both the x-axis and the y-axis shows that the product using the adhesive according to an embodiment herein is at all compared to a product made with a conventional binder system. The minimum corner wear is shown at the material removal rate.

Example 3

In this example, an embodiment comprising a combination of a sol-gel and a fused alumina abrasive is formed using the binder described above for the previous examples. This sample was tested in a centerless insert application to the finished form having a combination of sol-gel and fused alumina abrasive, using a conventional binder VH previously used for other examples, as compared to a conventional product. The grinding wheels have a diameter of 16 inches and the abrasive material is mild steel (1014). The goal is to increase productivity by increasing the number of parts per trim. The wheel speed is 57.45 m/s and the part speed is 1.15 m/s.

Table 2 contains more details regarding the test conditions used in Example 3.

Figure 10 includes a graph of the number of parts for each trim of the conventional bonded abrasive article 2000 and the bonded abrasive article 2005 of the present embodiment. Compared to item 2000, item 2005 shows a significant improvement (about 7% improvement) in the number of parts trimmed each time, and has a good surface finish or shape.

Another advantage observed is that the cross feed rate can be significantly increased for new wheels that help reduce cycle time. Lower cycle times have better efficiency in the grinding operation. Test the same sample described for Figure 10 Cycle time, and the results are shown in Figure 11. Figure 11 is a graph of cycle time for a conventional bonded abrasive article 2100 and a bonded abrasive article 2105 of the present embodiment. Item 2105 showed a significant (about 18%) improvement over item 2100.

The above embodiments are directed to abrasive products, and in particular bonded abrasive products, which represent deviations from the prior art. The bonded abrasive product of the embodiments herein utilizes a combination of features that promote improved abrasive performance. As described in this application, the bonded abrasive bodies of the embodiments herein utilize specific amounts and types of abrasive particles, specific amounts and types of binder materials, and have a specific amount of porosity. In addition to the discovery that such products can be efficiently formed (although in terms of their grade and structure beyond the known range of conventional abrasive products), such products have been found to exhibit improved abrasive performance. Notably, it was found that the bonded abrasive of the present embodiment is capable of operating at lower speeds during the grinding operation, despite having significantly higher porosity than conventional grinding wheels. In fact, very surprisingly, the bonded abrasive bodies of the embodiments herein exhibit the ability to operate at wheel speeds of less than about 60 m/s while also exhibiting improved material removal compared to prior art grinding wheels. Rate, improved corner retention, and a suitable surface finish.

In the above, references to specific embodiments and connections to certain components are illustrative. It will be appreciated that reference to a component that is coupled or connected is intended to disclose a direct connection between the components or an indirect connection by one or more intervening components as is known to be performed herein. The method in question. Therefore, the above disclosed subject matter should be considered illustrative and not All such modifications, enhancements, and other embodiments are intended to be included within the true scope of the invention. The scope of the present invention is to be determined by the broadest permissible interpretation of the scope of the claims and the equivalents thereof.

The Abstract of the Disclosure is provided to comply with the Patent Law and the Abstract is submitted with the understanding of the scope or meaning of the scope of the patent application. In addition, in the above Detailed Description, for the purpose of streamlining the disclosure, various features may be grouped together or described in a single embodiment. The disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are specifically described in the scope of each application. Rather, the subject matter of the present invention may be related to less than all features of any of the disclosed embodiments, as reflected in the scope of the following claims. The scope of the following claims is hereby incorporated by reference in its entirety in its entirety in the extent of

Claims (15)

An abrasive article comprising: a bonded abrasive body having abrasive particles contained within a binder material; wherein the binder material comprises an alkali metal having a total content of at least about 14% by weight based on the total weight of the binder material a combination of an oxygen compound (R ₂ O) and an alkaline earth metal oxygen compound (RO); and wherein the binder material comprises at least about 11% by weight and not more than about 17% by weight, based on the total weight of the binder material, of boron oxide ( B ₂ O ₃ ) content. An abrasive article comprising: a bonded abrasive body having abrasive particles contained within a binder material, the bonded abrasive body comprising an abrasive particle-binder material interface modulus of elasticity (MOE) of at least about 225 GPa And the bonded abrasive body is configured to grind a workpiece comprising metal at a speed of less than about 60 m/s, wherein the bonded abrasive body comprises a definition defined as a change in cross feed rate A varying grinding coefficient for the x-axis radius, and for a cross feed rate (Z'w) of at least about 1.0 inches per minute, the coefficient of grinding is no greater than about 0.040. An abrasive article comprising: a bonded abrasive body having abrasive particles contained within a binder material, the bonded abrasive body comprising an abrasive particle-binder material interface modulus of elasticity (MOE) of at least about 225 GPa ;and The bonded abrasive body is configured to grind a workpiece comprising metal at a speed of less than about 60 m/s, wherein the bonded abrasive body includes a y-axis defined as a function of a change in cross feed rate The varying coefficient of grinding of the radius, and for a cross feed rate (Z'w) of at least about 1.0 inches per minute, the coefficient of grinding is no greater than about 0.018. The abrasive article of any one of claims 1 to 3, wherein the bonded abrasive body comprises an abrasive grain-binder material interface hardness of at least about 13 GPa. The abrasive article of any of claims 1 to 3, wherein the bonded abrasive body is configured to grind a workpiece comprising metal at a speed of at least about 35 m/s. The abrasive article of any one of claims 1 to 3, wherein the bonded abrasive body comprises a porosity of at least about 42 vol% to about 70 vol% of the total volume of the bonded abrasive body, and The bonded abrasive body comprises at least about 35 vol% abrasive particles of the total volume of the bonded abrasive body. The abrasive article according to any one of claims 1 to 3, wherein the binder material is formed of at least one alkali metal oxy compound (R ₂ O) and at least one alkaline earth metal oxygen compound (RO), wherein The total content of the alkali metal oxy compound and the alkaline earth metal oxy compound is not more than about 20% by weight. The abrasive article of any one of claims 1 to 3, wherein the binder material comprises from about 9.6 to about 26 cerium oxide (SiO ₂ ) by weight percent to LiO ₂ weight percent (SiO ₂ : LiO ₂ ) ratio. The abrasive article of any one of claims 1 to 3, wherein the binder material comprises from about 4.8 to about 10.4 weight percent cerium oxide (SiO ₂ ) to weight percent Na ₂ O (SiO ₂ : The ratio of Na ₂ O). The abrasive article of any one of claims 1 to 3, wherein the binder material comprises from about 9.6 to about 26 cerium oxide (SiO ₂ ) weight percent to K ₂ O weight percent (SiO ₂ : K ₂ O) ratio. The abrasive article of any one of claims 1 to 3, wherein the binder material comprises from about 2.8 to about 5.2 cerium oxide (SiO ₂ ) weight percent to B ₂ O ₃ weight percent (SiO ₂ :B ₂ O ₃ ) ratio. The abrasive article of any one of claims 1 to 3, wherein the binder material comprises from about 0.2 to about 1 weight percent of Li ₂ O to weight percent of Na ₂ O (Li ₂ O: Na ₂ O) Ratio. The abrasive article of any one of claims 1 to 3, wherein the binder material comprises from about 0.4 to about 2.5 weight percent of Li ₂ O to weight percent of K ₂ O (Li ₂ O: K ₂ O) Ratio. The abrasive article of any one of claims 1 to 3, wherein the binder material comprises from about 1 to about 5 weight percent of Na ₂ O to weight percent of K ₂ O (Na ₂ O: K ₂ O) Ratio. The abrasive article according to any one of claims 1 to 3, wherein the binder material comprises cerium oxide (SiO ₂ ) by weight: the ratio of the weight percentage of alumina (Al ₂ O ₃ ) is not more than About 3.2 (by weight percent) and having phosphorus pentoxide (P ₂ O ₅ ) of no greater than about 3.0% by weight, wherein the bonded abrasive body has at least about 42 vol of the total volume of the bonded abrasive body % porosity.